


In the Deep Waters

by clusium_kiss



Category: Voltron: Legendary Defender
Genre: Alternate Universe, Alternate Universe - Merpeople, Angst, Breeding, Dubious Consent, Fluff, Instinct, M/M, Male Lactation, Merpeople, Mpreg
Language: English
Status: Completed
Published: 2018-08-12
Updated: 2018-08-12
Packaged: 2019-06-26 01:59:26
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,180
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/15653436
Author URL: https://archiveofourown.org/users/clusium_kiss/pseuds/clusium_kiss
Summary: Keith strays from his home waters and is soon caught and bred by Thace. Then he finds out he's not the only one Thace has caught.





	In the Deep Waters

**Author's Note:**

> This is completely self-indulgent. I have a huge merpeople breeding kink and NEED MORE. 
> 
> I based the merpeople biology here very loosely on dolphins, so this doesn't involve eggs. I've seen a few fics that use the term "guppy" for mer babies, and I find that cuter than "calf" while still being more non-human than "baby," so that's what I went with here. 
> 
> I've tagged it as dubious consent for instinctual mating urges. Keith doesn't want to be bred initially, so your mileage may vary on whether you consider it non-con or dub-con.

A school of mackerel, their silver scales tempting him with thoughts of the juicy flesh inside, lured Keith from his usual waters. The fish swam in a zigzag pattern, weaving around slanting beams of light filtering downward through the waves. They sensed his approach and sped up, and he chased after them, flicking his tail and putting on a burst of speed. He wasn’t particularly hungry at the moment, though, and it was amusing to pursue the darting fish. So he toyed with them, herding them into crannies of rock and coral and letting the tips of his sharp nails graze their fins. 

He was so immersed in the game that he failed to notice that he was swimming further and further away from the shallow cove where he made his home, into darker and deeper waters. 

He did catch one finally, and then another, tearing into their bellies with his pointed teeth. He swam into some kelp fronds to enjoy his meal, crunching the little bones and sucking out the sweet eyes. Intent on his food, he didn’t realize that the tip of his tail was sticking out of the kelp, the scarlet luster of his scales drawing the eyes of others who were swimming nearby. 

It happened quickly—strong fingers closed around the end of his tail and yanked him unceremoniously out of the kelp. Keith shrieked in alarm, his tongue clicking in an agitated rhythm, slashing at his unseen attacker with is nails. 

But his adversary was quick, dodging his strike. He had a confused glimpse of another mer—bigger than him, dark purple scales, and large, pointed ears—before arms closed around his chest, pinning his elbows and restraining him. 

Keith squirmed, beating his tail futilely against the other’s fins. The merman hummed, a deep, reverberating sound that buzzed against Keith’s back where it pressed against his chest. A rough, scaled cheek brushed along his chin, nuzzling. 

The absence of jagged teeth tearing his skin calmed Keith slightly. He grew quiet, although he continued to test the strength of the mer’s hold. 

The mer clicked, amused, and twined his tail around Keith’s. 

Keith whistled, a high, confused noise. Why wouldn’t the other let him go? If he wasn’t trying to hurt or kill Keith for trespassing in his territory, then why—

The mer redoubled the grip of his one arm, keeping Keith pinned, while his other hand slipped down Keith’s chest, petting his stomach, and then teasing the sensitive scales where his skin merged into his tail. 

Keith froze and then erupted in a frenzy of motion, trying to break free. He knew now why the mer had caught him. He wanted to mate with Keith, breed him, and fill him with his guppies. 

The mer started rumbling again, a deep, hypnotizing hum, but Keith didn’t want to calm down, didn’t want to be bred—he’d be defenseless, full and heavy with a stranger’s get, unable to swim quickly. He wanted to go home, back to the light, warm waters. He didn’t want to be dragged down into the cold dark of the deep and kept in some hidden cave until he gave birth. 

But the mer was crooning now, and his tail was rubbing up and down Keith’s, soothing, tantalizing. A hand stroked his hair and teased the pointed edge of his ear. Keith mewled, torn between panic and arousal. 

The mer’s song grew softer yet clearer, and Keith’s movements grew lax and heavy. They were sinking together, drifting deeper. He was cradled in the other’s arms and tail. One last struggle, straining upwards, and then he went limp, unable to fight any longer. 

Gently, he was turned around. Glowing yellow eyes met his own. Keith blinked and then clicked and whistled, nervous and unsure. 

The other rubbed his nose against Keith’s, calming. And then he was being pushed down, so he was on his back. It was awkward and vulnerable, but Keith couldn’t do anything about it, still held fast, his will to fight suppressed by instinct, his genital slit fluttering open, unbearably sensitive as it brushed against the other’s scales. He keened. 

The mer kept petting his hair and pressed close. Keith couldn’t see it, but he felt the other’s cock emerge, poking him, seeking his entrance. They undulated in the water, the mer shifting until the head of his cock found Keith’s slit and probed inside. 

He had never been bred before—never breached by something so large—and it ached even as he opened around it. The tip of cock was pointed, and it nudged against Keith’s inner passage, sending shocks of pleasure through his body. It penetrated further, unfurling inside him. 

The mer flexed his hips, withdrawing and then pushing forward, a rhythm that soon had Keith whimpering in ecstasy. He was empty, he realized—so empty. He needed the thickness of the cock, needed it there inside him, needed more too—the hot, sticky rush of come filling his womb and fertilizing his eggs. 

The mer gave him what he wanted, driving deep and holding in place. Keith could feel his cock pulsing as it released his seed, and then his own orgasm rushed over him, leaving him shaky and weak in the aftermath.

They drifted for a while, the mer’s cock still lodged inside him, still letting out occasional bursts of seed. Keith huddled in the mer’s arms, overwhelmed, letting the mer’s satisfied croons soothe him. 

The mer touched their foreheads together, and Keith accepted the other’s name-- _Thace_ \--and exchanged his own. 

_Mate_ , Thace thought, and Keith could feel his pride at having caught and bred him, how lovely he thought Keith’s tail was, and how he was going to care for Keith in the coming months, keeping him fed and warm and making sure he had been impregnated. 

Keith didn’t even try to resist when Thace finally slipped out of him and towed him gently through the dark currents, Thace’s seed warming him in the cold water. 

Thace made his home in a secluded tunnel that wound through rocks and finally ended in a cave. Bioluminescent plants growing in crevasses in the walls shed a dim light, but the corners remained in shadow. Something moved in the darkness, and to Keith’s shock, another mer swam into view. He moved slowly and clumsily, despite his long, flowing blue tail, and Keith realized that his stomach was slightly rounded. Thace must have bred him too, and he was already growing heavy with guppies.

The new mer did not seem too pleased at Keith’s arrival. He pouted and turned big, betrayed eyes on Thace, who appeared unmoved by this display, merely rubbing his cheek against the mer’s in a greeting and then twisting them around so he could put his arms around him and cup his stomach in his large, webbed hands. 

Keith hung back, unhappy and cold without Thace’s warmth around him. But when Thace gestured for him to join them, and Keith swam hesitantly closer, the other mer hissed and swiped at Keith with his nails. Keith hissed back, annoyed. It wasn’t like he’d _asked_ to be caught and mated. 

Their altercation made Thace angry. His fins flared, and he let out a sharp booming growl that reverberated through the water. It hurt Keith’s ears, ringing in his head. The other mer shrieked and wound himself into a ball, covering his head with his arms. 

Thace swam back to Keith, clicking in apology. He touched their foreheads. _Lance_ , he told Keith, gesturing at the other mer, who was now sulking in a corner, only the tips of his tail visible. _Mate_.

Keith clicked back, still upset. As if it wasn’t bad enough that he’d been taken from his home waters, now he discovered that he wasn’t the only mer Thace had bred. 

Thace crooned and coaxed Keith into his arms, stroking his ears again. His other hand drifted closed to Keith’s slit, teasing, and Keith squirmed, his tail twining with Thace’s. 

It wasn’t long before Thace flipped him and slid into position, letting his cock emerge. Once again, Keith found himself overcome with the pleasure of feeling so full, his passage stretched, Thace’s cock rubbing the sensitive nerves. It was while Thace was rolling his hips, thrusting in and out, that Keith realized Lance had emerged from the corner and was watching them. Lance’s eyes glowed in the bluish-green light. 

Thace stilled and started spurting seed into Keith. It drew Keith’s attention away from Lance, but a few moments later, hands touched his stomach, and he looked down to see Lance stroking him there, where Thace was fertilizing his eggs. 

Thace crooned, proud, and wrapped an arm around Lance, pulling all three of them together. Lance settled against Keith and nudged his chin in an apology for earlier.

Keith fell asleep like that, Thace still inside and keeping his seed plugged in Keith’s womb, with Lance nuzzling him and lazily curling their tails together. 

The next day, Keith woke just as Thace was preparing to leave to hunt food for them. Lance detached from Keith’s side to go say farewell, clicking insistently at Thace and churning the water into bubbles in his hungry impatience. 

Keith’s head felt clearer, no longer overwhelmed with mating urges. He wondered if Thace had successfully bred him. He was sure that if he remained here, Thace would keep mounting him until there was no doubt that he had succeeded. This was his chance, then, to escape while Thace was off hunting.

But no sooner had he approached the tunnel entrance then Lance was there, clicking and whistling at him, agitated and distressed. He tugged at Keith’s arm, pulling him back. It was dangerous out there, he was telling Keith. It was dangerous in the dark waters, with unseen predators. They needed to stay here, safe, and wait for their mate. 

Keith looked longingly at the tunnel. Lance pushed him, herding him backwards. 

And Keith didn’t fight him. If Thace had impregnated him—it would only be a matter of time until he got too clumsy and slow to swim well. And what would he do once the guppies came? He needed a mate to provide for both of them and protect them. 

So he let Lance show him around the cave and tried not to reveal his homesickness and anxiety. 

There was a fissure in the back of the cave where warmer water seeped through in a stream of bubbles. Keith immediately curled up there, grateful for the warmth. Lance trilled, smiling and showing Keith the sharp points of his teeth, then swam off, returning with his hands full of strings of pearls and a comb. It soon became apparent that he wanted to brush Keith’s hair and braid the pearls into it. 

Keith raised his fins, but Lance turned pleading eyes on him, and Keith’s resolve wavered. Soon, Lance was happily playing with his hair, trilling and humming a song. 

Thace certainly seemed to like the results of Lance’s meddling if the eagerness with which he mounted Keith when he returned was any indication. Thace had brought back a net full of fish, and Lance fell on them like a shark in a frenzy, but when he’d eaten his fill, he swam over, picking bones out of his teeth, and twined around them in a lazy, sated stretch. He slid a finger into Keith alongside Thace’s cock, and Thace and Keith keened in tandem at the sensation. When he’d finished with Keith, Thace mounted Lance too, even though Lance already exhibited ample signs of a successful breeding.

Keith curled on his side, burrowing a little into the sandy bottom of the cave, and wrapped his arms around his stomach. 

It was difficult to keep track of time in the unchanging darkness of the deeps, but Keith was sure it wasn’t too long before he woke feeling nauseous and refused the fish and crustaceans that Thace hunted for them. Everyone knew what it meant, of course, and Thace held Keith and stroked his ears, proud at this proof of his virility and the expectation of more guppies. Meanwhile, Lance concocted some sort of medicine and clicked at Keith until he swallowed it. It did help with the nausea, but he still turned away from the food. He felt cold, deep down into his bones. 

Lance curled around him, letting out worried clicks as he pawed at Keith’s tail and nudged at his chin with his nose. Thace hovered over both of them and then gathered Keith close again and touched their foreheads. 

_Hurt?_

He wasn’t hurt—not physically at any rate. He thought longingly of home—bright waters, sparkling waves—of how it felt to splash and play in the surf. But another part of him knew that Thace had caught him and mated him. He belonged here now. Not just for breeding, either, a fact reinforced later when Thace began teasing his slit and nuzzling his neck until Keith was writhing in his arms in eager anticipation of taking Thace’s cock. Lance squirmed against them, touching fins and ears, and Thace rumbled approvingly when Keith slipped hesitant fingers into Lance. 

It wasn’t really a surprise the next day when Thace had left to go hunting that Lance came up behind Keith and wrapped his arms around his middle, letting their fins rub together. Lance trilled, questioning and hopeful. 

Well, it was better than spending the hours feeling cold and homesick. Keith turned around and let Lance guide his mouth to his chest, where his breasts had been getting puffy and his nipples red and sore as his milk came in. Keith suckled and licked obediently, mindful of his teeth, while Lance whimpered with relief. 

Thace came back to find them still entwined, fingers fucking into each other’s bodies, and Keith’s pale neck covered in reddened bite marks. He watched them for a while, his cock slowly emerging from its sheath, and then finally motioned for them to swim to him. He cupped a hand on each of their heads and guided their mouths to his cock, having them suck the head in turns until he was ready to finish with a few thrusts into Lance while Keith held Lance from behind, helping him balance given the growing swell of his stomach. 

It turned out Thace had brought more bioluminescent plants as well as fish to eat. The plants made it a bit brighter in the cave, and Keith knew Thace was trying to make up for the sunlight that Keith missed. His heart beat a little faster, and he clicked at Thace hopefully. Perhaps, if Thace was willing to do this, he would let Keith—

But Thace shook his head and put himself in between Keith and the tunnel entrance. He stroked Keith’s stomach and tugged on one of the pearl strands Lance had woven in Keith’s hair. It was safe here, and Thace wanted to protect both Keith and their guppies. 

Keith nodded, heart sinking again, and swam into a corner to brood until Lance started teasing him with a kelp frond, tickling Keith’s fins and making Keith hiss and snap his teeth. Lance stuck out his tongue and went to snuggle with Thace, well out of the reach of Keith’s nails. Keith held out as long as he could but finally went to join them, needing the warmth of their bodies. 

It struck Keith the next day that Lance was going to be giving birth before he did, and that with Thace often away hunting, there was a good chance that he would be alone with Lance when it happened. The thought filled him with a sharp anxiety. His pod had been decimated by hunters when he was small, leaving only him and his father. He had never witnessed a birth before and didn’t know what to do if something went wrong. 

Lance swam over, whistling and chirping, wanting to nuzzle and play. Keith bristled his fins, hissing, and when Lance came closer, concerned now, Keith swiped at him, drawing a trio of red, angry lines across Lance’s shoulder. Lance shrieked and retreated, wounded. Stomach churning with guilt and fear, Keith went to the warm stream of bubbles in the back of the cave and curled up there. He had been alone before, yes, but carefree, able to swim in the sunny waters and catch fish and investigate reefs. Now he had a mate and would soon have guppies to look after, and there was also Lance and his own prospective children. It was… it was like they were forming a pod. Keith didn’t want a pod—he’d been part of one and it had been taken away from him. If something happened to Lance when his guppies came…

The hours passed slowly until Thace returned. Lance didn’t try to approach him again, probably angry (rightfully so) at the unprovoked attack. He expected Thace would be angry too, and he curled into a tighter ball, fins flaring, when he heard Thace arrive. 

But when Thace did come to him, he didn’t growl or threaten. Instead, he brought Keith the choicest portions of fish from the day’s hunting. As Thace always let Lance and Keith eat first, and Lance usually devoured at least three quarters of the juiciest delicacies before Keith could get to them, he knew that Lance must have refrained from eating and insisted that Thace bring this to Keith. Why? Why had he done it when Keith had hurt him?

Thace clicked at him, and Keith slowly took a piece of fish, chewing carefully. It was delicious, but he could hardly swallow past the lump in his throat. He realized Lance was hovering in the background, looking worried, the scratches Keith had put on his shoulder red and raw. 

Unable to stand it any longer, Keith darted to Lance, plowing into him with a thump and pushing their foreheads together. Images of blood and torn flesh—the fate of his last pod—the fear that it could be Lance next—that he or his guppies would die and Keith would be helpless—

Lance crooned and caught Keith in his arms, shock transforming into understanding. He gave Keith his own memories—his pod with his mother and siblings—one of his sisters giving birth—the excitement—small guppies clinging to his tail. They would be all right. Lance wasn’t afraid, and Keith didn’t need to be either. 

The effort of sharing such intense emotions drained both of them, and they sank to the sandy floor, still wrapped around each other. Then Thace was there, with his strong arms, lifting them up, letting them rest on his broad chest. He coaxed them into eating the fish, feeding them from his fingers. Keith was so tired his eyes closed in between bites, but for the first time since Thace had brought him here the dark, cold waters did not press upon him so heavily, the yearning for his home waters muted under the attachment to his mate, Thace, and his friend, Lance. 

As it transpired, Thace _was_ away when Lance’s guppies decided to arrive, and Keith still felt scared. But he did the best he could, helping Lance to swim and letting him grip his hands tightly as his inner muscles strained. The guppies came out tail first—two of them in quick succession. One had very pale blue scales and the other violet. Keith marveled at their tiny hands and ears. Their gills fluttered, and Lance, still breathing hard, brought them to his nipples, getting them to suck their first milk. Keith watched closely, knowing he would need to do the same in a few tides time. 

When Thace returned, he was overjoyed, crooning to Lance and his children, letting the guppies curl their tails around his wrist and practically smothering Lance with his nuzzling. Keith might have felt a bit left out, except when Lance and the babies had gone to sleep, the guppies carefully sheltered in the circle of Lance’s tail, Thace took Keith to the warm bubbles and held him, stroking the swell of his stomach and licking at his nipples to ease their soreness. 

Keith rubbed at Thace’s sheath until his cock emerged and then rolled onto his back, wanting the pleasure of Thace inside him. He wondered if Thace would keep him after their guppies were big enough to swim on their own. Or had Thace only wanted to breed him for a season? Perhaps Thace would only keep Lance to mate with. Keith would have to leave and might be caught by another mer, bred full again by a stranger. Thinking it made him mewl sadly. He didn’t want to leave Thace and Lance, not even to go back to his home. 

Keith’s own time came in the middle of their sleep cycle, and soon everyone was roused, Lance’s guppies shrieking thinly in distress until Lance calmed them. Thace gripped Keith’s arms while Keith undulated, muscles rippling as he did his best to push. Had it hurt this much for Lance? He could smell blood too, and while he remembered blood clouding the water after Lance gave birth, it was still frightening. 

He hardly realized it was over, still dealing with the last aftershocks of pain, until he felt a feather-light touch on his scales and looked down to see his guppy pawing at him with its tiny webbed hands. Its scales were a pearlescent white, tinged with red and purple on the tips. With Lance’s help, he got its mouth latched onto a nipple, and he stroked its tiny head, suffused with a fierce protectiveness. 

There was only one guppy, though, and he felt a moment’s trepidation that Thace would be disappointed, but this was instantly dispelled by the joy in Thace’s expression and how tightly he twined their tails together, holding Keith close and resting his chin on Keith’s shoulder so he could watch their guppy nurse. 

With only one guppy, Keith soon found himself helping nurse Lance’s too. The blue-scaled guppy in particular soon learned that it could get milk from both Lance and Keith and was noticeably chubbier than its sibling or Keith’s own guppy. Keith grumbled at it a little but could never turn it away either. Thace was kept busy catching fish, as both Lance and Keith were almost always hungry, producing milk for the guppies and swimming more freely now that neither were weighed down with babies inside them. 

Indeed, Keith was soon feeling restless and thinking longingly of the open ocean outside the cave. 

The guppies grew quickly, and he began half-expecting the day to come when Thace would herd Keith and his guppy from the cave, sending them off to fend for themselves. 

But to his shock, instead of sending Keith away, one day Thace and Lance began packing up _all_ their possessions. The guppies swam about in excitement, sensing that some new adventure was beginning. 

Seeing Keith’s confusion, Thace swam over and took his hand, nudging their foreheads together. _Home_ he told Keith, and gave him the image of the shallow cove where Keith had lived. 

Keith stared at him, hardly daring to believe it. Did Thace really mean for their pod to make a home there? 

Lance came over, clicking and grinning his pointed-teeth grin, nudging Keith toward the tunnel. 

Keith swam in a daze, although he remembered the way—remembered it perfectly—back up, up through the cold currents into warmer waters, back through the forests of kelp and past the twisted rocks, back up to where the sunlight lanced through the waves. His guppy became tired halfway there and clung to his tail, while Lance’s attached themselves to Thace’s shoulders. Lance seemed to be everywhere at once, darting about, happily investigating shiny things that caught his eye.

And then they were there, in his old, familiar waters, where he had swum with his father long ago. They would need to find a new place to live—the small space Keith had made for himself in a reef would never fit all six of them. But he couldn’t think about that now—all his desire was concentrated on the surface of the water. He breached it, flinging himself above the waves, holding his breath as the wind struck him, curving into a dive like a dolphin, and then plunging back into the foaming swell of the ocean. 

Lance jumped too, clicking with delight, and soon their guppies were all trying to imitate their movements—Keith felt that _his_ did the best—while Thace swam lazy circles underneath them. 

Perhaps, when Thace had bred him and Lance again, they would need to go back to the deep cave to birth their guppies, but Keith knew that they would always return here. Their guppies would live here too, and perhaps bring their own mates here one day. 

The waves rolled, and Keith leapt and dived, scales glinting in the sunlight, his ears catching the far-off sound of the surf pounding against the shore.


End file.
